Method of remapping hybrid automatic repeat request timeline in time division duplex uplink-downlink reconfiguration

Abstract

A method of remapping Hybrid Automatic Repeat Request (HARQ) timeline in Time Division Duplex (TDD) uplink-downlink (UL-DL) reconfiguration, for a communication device in a wireless communication system is disclosed. The method includes being reconfigured from a first TDD UL-DL configuration in a first radio frame to a second TDD UL-DL configuration in a second radio frame, determining a TDD UL-DL reference configuration according to UL subframe allocations of the first and second TDD UL-DL configurations in the first radio frame, and performing HARQ processes of the first TDD UL-DL configuration according to a HARQ timeline of the TDD UL-DL reference configuration during the first and second radio frames.

What is claimed is: 
     
       1. A method of remapping Hybrid Automatic Repeat Request (HARQ) timeline in Time Division Duplex (TDD) uplink-downlink (UL-DL) reconfiguration, for a communication device in a wireless communication system, comprising:
 being reconfigured from a first TDD UL-DL configuration in a first radio frame to a second TDD UL-DL configuration in a second radio frame on a carrier; 
 determining a TDD UL-DL reference configuration according to UL subframe allocations of the first and second TDD UL-DL configurations in the first radio frame, wherein the TDD UL-DL reference configuration has the least number of UL subframes among all TDD UL-DL reference configurations which include all UL subframes both in the first and second TDD UL-DL configurations; 
 performing HARQ processes of the first TDD UL-DL configuration according to a HARQ timeline of the TDD UL-DL reference configuration during the first and second radio frames on the carrier; and 
 performing UL HARQ processes of the second TDD UL-DL configuration according to a HARQ timeline of the second TDD UL-DL configuration during the second radio frame on the carrier. 
 
     
     
       2. The method of  claim 1 , wherein performing HARQ processes of the first TDD UL-DL configuration according to a HARQ timeline of the TDD UL-DL reference configuration during the first and second radio frames comprises:
 determining whether a UL subframe of the TDD UL-DL reference configuration in the second radio frame mapped by a DL HARQ process of the first TDD UL-DL configuration in the first radio frame is a UL subframe of the second TDD UL-DL configuration in the second radio frame; 
 determining whether a DL subframe of the TDD UL-DL reference configuration in the second radio frame mapped by a UL HARQ process of the first TDD UL-DL configuration in the first radio frame is a DL subframe of the second TDD UL-DL configuration in the second radio frame; 
 mapping the DL HARQ process of the first TDD UL-DL configuration in the first radio frame to the UL subframe of the second TDD UL-DL configuration in the second radio frame when determining the UL subframe of the TDD UL-DL reference configuration in the second radio frame is the UL subframe of the second TDD UL-DL configuration in the second radio frame; and 
 mapping the UL HARQ process of the first TDD UL-DL configuration in the first radio frame to the DL subframe of the second TDD UL-DL configuration in the second radio frame when determining the DL subframe of the TDD UL-DL reference configuration in the second radio frame is the DL subframe of the second TDD UL-DL configuration in the second radio frame. 
 
     
     
       3. The method of  claim 2 , further comprising:
 stopping the DL HARQ process of the first TDD UL-DL configuration in the first radio frame when determining the UL subframe of the TDD UL-DL reference configuration in the second radio frame is not the UL subframe of the second TDD UL-DL configuration in the second radio frame; and 
 stopping the UL HARQ process of the first TDD UL-DL configuration in the first radio frame when determining the DL subframe of the TDD UL-DL reference configuration in the second radio frame is not the DL subframe of the second TDD UL-DL configuration in the second radio frame. 
 
     
     
       4. The method of  claim 1 , further comprising:
 being allocated a uplink grant in a DL subframe of the first TDD UL-DL configuration in the first radio frame according to the HARQ timeline of the TDD UL-DL reference configuration when a UL subframe of the TDD UL-DL reference configuration in the second radio frame is not mapped by a DL HARQ process of the first TDD UL-DL configuration in the first radio frame. 
 
     
     
       5. A mobile device of a wireless communication system for remapping Hybrid Automatic Repeat Request (HARQ) timeline in Time Division Duplex (TDD) uplink-downlink (UL-DL) reconfiguration comprising:
 a processing means for executing a program; and 
 a storage unit coupled to the processing means for storing the program; wherein the program instructs the processing means to perform the following steps: 
 being reconfigured from a first TDD UL-DL configuration in a first radio frame to a second TDD UL-DL configuration in a second radio frame on a carrier; 
 determining a TDD UL-DL reference configuration according to UL subframe allocations of the first and second TDD UL-DL configurations in the first radio frame, wherein the TDD UL-DL reference configuration has the least number of UL subframes among all TDD UL-DL reference configurations which include all UL subframes both in the first and second TDD UL-DL configurations; 
 performing HARQ processes of the first TDD UL-DL configuration according to a HARQ timeline of the TDD UL-DL reference configuration during the first and second radio frames on the carrier; and 
 performing UL HARQ processes of the second TDD UL-DL configuration according to a HARQ timeline of the second TDD UL-DL configuration during the second radio frame on the carrier. 
 
     
     
       6. The mobile device of  claim 5 , wherein performing HARQ processes of the first TDD UL-DL configuration according to a HARQ timeline of the TDD UL-DL reference configuration during the first and second radio frames comprises:
 determining whether a UL subframe of the TDD UL-DL reference configuration in the second radio frame mapped by a DL HARQ process of the first TDD UL-DL configuration in the first radio frame is a UL subframe of the second TDD UL-DL configuration in the second radio frame; 
 determining whether a DL subframe of the TDD UL-DL reference configuration in the second radio frame mapped by a UL HARQ process of the first TDD UL-DL configuration in the first radio frame is a DL subframe of the second TDD UL-DL configuration in the second radio frame; 
 mapping the DL HARQ process of the first TDD UL-DL configuration in the first radio frame to the UL subframe of the second TDD UL-DL configuration in the second radio frame when determining the UL subframe of the TDD UL-DL reference configuration in the second radio frame is the UL subframe of the second TDD UL-DL configuration in the second radio frame; and 
 mapping the UL HARQ process of the first TDD UL-DL configuration in the first radio frame to the DL subframe of the second TDD UL-DL configuration in the second radio frame when determining the DL subframe of the TDD UL-DL reference configuration in the second radio frame is the DL subframe of the second TDD UL-DL configuration in the second radio frame. 
 
     
     
       7. The mobile device of  claim 6 , wherein the program further comprises the following steps:
 stopping the DL HARQ process of the first TDD UL-DL configuration in the first radio frame when determining the UL subframe of the TDD UL-DL reference configuration in the second radio frame is not the UL subframe of the second TDD UL-DL configuration in the second radio frame; and 
 stopping the UL HARQ process of the first TDD UL-DL configuration in the first radio frame when determining the DL subframe of the TDD UL-DL reference configuration in the second radio frame is not the DL subframe of the second TDD UL-DL configuration in the second radio frame. 
 
     
     
       8. The mobile device of  claim 5 , wherein the program further comprises the following steps:
 being allocated a uplink grant in a DL subframe of the first TDD UL-DL configuration in the first radio frame according to the HARQ timeline of the TDD UL-DL reference configuration when a UL subframe of the TDD UL-DL reference configuration in the second radio frame is not mapped by a DL HARQ process of the first TDD UL-DL configuration in the first radio frame.